


Undertale AU consepts

by Sketchy_Vore



Category: Undertale (Video Game)
Genre: /, Alternate Universe - Gaster Blaster (Undertale), Alternate Universe - Underfell, Desert, Gaster Blaster Papyrus, Gaster Blaster Sans, Giant Sans, Mountains, Other, Platonic Relationships, Platonic vore, Scientist W. D. Gaster, Soft Vore, Vore, Warfell, safe vore, story in the past, villages
Language: English
Status: In-Progress
Published: 2017-11-05
Updated: 2018-03-19
Packaged: 2019-01-29 13:33:59
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 8,048
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12632088
Author URL: https://archiveofourown.org/users/Sketchy_Vore/pseuds/Sketchy_Vore
Summary: So, since I suggested it and people agreed: Here are the descriptions of several AUs that just aren't fleshed out enough to be a full-fledged AU or that I'm just too tired to write it as a full story.Though one day I might, I don't know?But if you think you can do something with these AUs, please contact me so I can see how it goes and you are more than free to use them.





	1. Deserttale

**Summary for the Chapter:**

> In this one, we have Gaster Blaster Sans and Papyrus, and they are originally scientifically created for war. All the rest of the characters are humans.

This AU takes place in a post-apocalyptic desert-like world where civilizations fight over water.

In a big city that has taken claim over the largest sources of fresh water, a scientist is ordered to create a weapon to conquer more water-settlements so the city can control them instead. The scientist does what is asked, but as his creations, called Gaster Blasters, grow and start to show self-awareness and intelligence, he refuses to let them be used for military gain. When he tries to go into hiding he is promptly shot for ‘treason’.

When the government tries to take control of the two creations, however, they quickly bump into a huge problem: The scientist could not speak, and he wrote and signed in his own made-up language. So they can’t use his notes to create more weapons (most of the notes were burned beforehand anyway), and the two existing creatures were trained in and would only answer to the doctor’s sign language. They do end up finding a use for the two brother creations though, as a method of execution.

The two creatures, especially the younger one, do have a strong instinct to kill ‘corrupted’ people (murderers, rapists, high degree abusers, etc.), and they find out the older of the two will do anything to keep his brother from harm. They turn it into some kind of game show (a la Hunger Games) where they send criminals (both major and minor, they pull straws to pick them) into a jungle enclosure where they have to run and try to survive, with the two creations on their heels, until all of them are dead. Usually, it takes just a day, once a month, with Papyrus impulsively (and not remembering afterward) going after the heavier criminals while Sans goes after the more ‘innocent’ people to spare his brother from doing so.

Frisk is a mute orphan living in the streets. They know the universal sign language that is used by the people, but ever since birth, they also know another kind of signing. It just came to them ever since birth, no one else understands it, and they sometimes mistakenly start to sign in it, especially when they’re nervous.

One day Frisk get’s caught for trying to steal some food and their number is drawn to be executed. They and about 9 other criminals are released into the arena, where they immediately scatter to get out of there before the two monsters are released. Frisk hides and it actually takes Sans quite a while to find them. When he does there is a short chase before he corners them. In their panic, Frisk starts to plead for their life in their own sign language and Sans actually stops, confused. To keep up the show he pretends to eat Frisk whole, while actually keeping them safe inside his jaws as he smuggles them into their stables.

Once Sans is sure no one will see the kid, he spits them out and Papyrus and he instantly starts to feel a kinship with the child. In turn, Frisk’s brain starts to fall in tune with the two brothers. Their movements, their sounds they make, even the way the brothers glance at something/someone, it all makes sense to them. Eventually Frisk learns the codes that unlock the stable doors and shock-collars of their friends and they manage to escape into the desert outside the city.

After running for hours (and Frisk suffering under the burning sun) they decide to stop near a tiny settlement. It is built in the Ruins of a village that died out after it’s well dried up, but the new inhabitants found a way to dig the old well deeper and be more thrifty with the new water source.

The trio decides for Sans and Papyrus to stay hidden in the dunes while Frisk goes to see if they can get their hands on food and water. Frisk get caught (again) trying to steal some apples, but this time by an elderly lady that gently scolds them instead. When Frisk admits that they don’t have a home or family to return to the lady introduces herself as Toriel and invites Frisk to stay with her. Frisk refuses and tells Toriel that they have to return to their ‘brothers’. After being offered and once again refusing for them and their ‘brothers’ to stay with her, she buys a bag of apples and a waterskin for all of them. She also gives Frisk 3 large pieces of fabric they can build a shelter from against the burning sun and freezing night: A long strip of red cloth, a blue, aras style rug with fluffy white tassels at the ends, and a blue and purple striped shawl.

They put the red fabric around Papyrus’ neck (so they don’t lose each other in a sandstorm), the rug around Sans’ rib cage (to protect and hide his fragile soul) and they themself wrap the shawl around their head (against the sun).

Before they can leave though, another tribe appears with the intent to take over the tiny oasis. Within the community of the Ruins, there are only a few person that is both trained and able enough to fight off the intruders, lead by captain Undyne.

Undyne’s forces are too small and she desperately fights off the nomads to try and save her village, and then it turns into a struggle so her wounded soldiers can be brought back to safety. Witnessing the clash between the honest desire to protect her loved ones and simple greed, Papyrus’ instincts kick in and he rushes into battle. Sans and Frisk don’t have much choice to go after him.

The opposing forces rapidly grow frightened of these two strange, powerful creatures and their ‘rider’, and they quickly decide to retreat. They take Undyne back to the village, where they are met by its equally terrified inhabitants. Toriel, however, recognizes the articles of clothing the trio is wearing. She introduces herself as the leader of the settlement and tells Frisk that, even though she now realizes why they refused her offer before, all three of them are more than welcome to stay with her. They accept this time.

Then Undyne and Papyrus quickly grow to be friends and battle-buddies, though she’s kinda pleasantly surprised that this ferocious war machine she saw before, is actually a giant, friendly skeleton puppy. Alphys, who is now the village’s scientist, used to work for Gaster, she was lucky to escape since Gaster told her to get out of the city before he could start packing. Thus she actually knows the brothers inside and out and helps to train them and bring out their full potential.

Together they’ll be going against the misguided Asgore (unstable after the death of his children during an accident with the escape of a few criminals) and his wicked and power-hungry advisor, Flowey.


	2. Mountain King

**Summary for the Chapter:**

> The Mountain King is one of my favorites.
> 
> Sans is a bitter giant who finds friendship and family in a 'cursed' human child.

The villages of a mountain range are terrorized by a skeletal giant. The legends go that a god had betrayed his kin and thus was cast from heaven. Taken by bitterness and vengeance the god lost his heart and everything else soft and vulnerable on his body, leaving a cold, marble white skeleton to roam the earth for eternity. He is often called the King of the Mountains, because he is always seen wearing a royal blue cloak with a white-furred collar, and because he decides who lives or (more likely) dies if they dare to climb the mountains. If he is in a mild mood, however, some have been known to survive if they win a game against him.

Frisk and Chara are two children living in an orphanage and care for each other like siblings (Chara is the younger of the two). Both have been brought there because children get a prophecy from the moment they are born, and those for Frisk and Chara were less than favorable.

 **Frisk:** _'_ _Your fate will be chosen by the mountain’s maw.'_

 **Chara:** _'_ _The person you love most will take the blade meant for you.'_

Everyone always looks at Frisk with pity since they are more than sure they’ll die in the mountains, or even by the King himself. Chara, on the contrary, is constantly shunned and people are always trying to drive them away out of fear that they might grow to care about them, thus making them the victims of the child’s prophecy. Chara is pretty bitter towards most humans because of this.

They are however always welcome at lady Toriel’s house. She is considered too old to adopt and properly care for any children, but Frisk and Chara always go there to keep her company and help around the house. Chara often wondered if Toriel wasn’t worried about their prophecy, to which she laughed and said that with whatever little time she had left in this world, she’d gladly give it to save them.

One day Toriel is out of firewood and Chara quickly volunteers to get more near the foot of the mountain. Frisk quickly offers to do it in their stead, it’s misty outside and Chara might be a little more helpful cooking then hauling around twigs and logs.

Because of the fog though, Frisk starts to wonder higher and higher up the mountain, only to realize how high up they are when they bump into a huge, skeletal leg.

Sans isn’t in the best mood because of the cold, wet weather, but he does end up challenging Frisk to a riddle game, because they’re just a lost kid. Each taking turns they both have to ask the other a hundred riddles, the one who answers most wins the game.

Frisk notices after about 60 riddles that they are losing, they aren’t that good at riddles and Sans has had way more experience with them. So in the hope to throw Sans off guard, they tell him a joke riddle. Sans is completely taken aback, his cold, sly composure cracks, and before Frisk’s very eyes, the feared King of the Mountains starts to giggle like a child.

With a smile that now looks genuine instead of mocking, Sans informs them that for every one of those that can make him laugh, he’ll take away two of their losses. With some new hope Frisk keeps on playing the game, but they quickly lose that hope as Sans suddenly starts to ask way more complicated riddles, as if he really want’s them to lose.

After a few more Frisk just gives up, realizing they can’t win this anymore. Sans frowns at this and hisses that in that case, he’ll take his prize. He dangles them over his mouth, causing Frisk to freak out, and once he drops them in they faint out of fear.

When they wake up though, they’re inside a huge room, locked in a cage. Sans notices them waking up and tells them that he liked their jokes, so now they’ll be staying here until they stop amusing him.

The first days are extremely stressful, with Sans threatening Frisk’s life if they’re stubborn and unwilling to tell jokes. But after Frisk literally blocks up and faints because of the stress and Sans fails to recognize it for a while, Sans becomes a little more patient (as long as he can laugh at jokes instead if that guilt gnawing at the back of his mind over a tiny limp body in his hands).

As it starts to get harder to think of new jokes, Frisk also starts to tell stories. First funny things that happened to them, Chara and Toriel, then stories and even songs known by their village, and eventually Sans starts to show interest in their personal life, not just the things that make him laugh. He even shares some small talk when it relates to their stories.

Sans starts to grow fond of Frisk, putting their cage on the table instead of dangling high above the floor, looking for stuff to make the cage more comfortable, having mealtimes with them, allowing them to sit on him in the easy chair when they tell stories, ect. He also starts to get more uncomfortable when Frisk recites stories the village tells about him. He wants to give Frisk more freedom and see them being happy, but after everything that has happened he feels a bit awkward to talk about it.

Frisk, however, has been told their whole life that the Mountain King is heartless and apathetic towards others, so they don’t notice any of this.

Frisk usually tries to think out a routine for the day after before they go to sleep: Fists some funny stuff to get him in a good mood, then some calmer things to keep him content for the rest of the day. A few weeks after Sans first caught Frisk, they have a much harder time thinking about what jokes or stories to tell. They stay up all night trying to think of something until they hear Sans’ voice greeting them in the morning.

Frisk blurts out the first joke that comes to mind, but they mess it up and Sans has heard it already anyways. Sans get’s worried over Frisk’s behavior, and Frisk mistakes his look for displeasure. So they start to ramble out jokes ( ‘yeah, a sunburnt penguin, you told me that one‘ ) and pieces of stories ( ‘wait, does this one relate to that story where you and Chara got chased by chickens?’ ) until they start to slip into a panic attack.

Sans tries to reach for them, but Frisk scrambles back as they plead for their life and promise they can come up with more jokes until they start to hyperventilate so badly that they faint.

When they wake up they are confused at their soft, glowing surroundings and the warm, blue liquid they’re sitting in, until they remember that Sans might have just eaten them, deciding they weren’t entertaining anymore. As Frisk starts to panic again, Sans gently confirms where they are, but also promises that ‘it won’t hurt’ and to ‘rest, it’ll be over soon’.

Frisk starts to cry at this, not wanting to die. Who is gonna take care of Chara and Toriel now after all? But Sans’ promise is a tiny bit reassuring (maybe he’s making it painless because he is a bit grateful for entertaining him for a while). Frisk eventually lets their hopelessness and exhaustion pull them back to sleep.

They wake up to a faceful of soft, white fur and blue fabric cozily wrapped around their body. It takes them a few confused seconds to realize that they are very much alive and not inside Sans’ stomach anymore, but wrapped up in his cloak on top of the easy chair instead.

When Sans returns into the room Frisk quickly hides under the cloak but Sans just lifts the edge to slide a plate with berries underneath with them, saying he understands if they’re scared, but he just wants to talk. He won’t be impatient though, they can come out in their own time.

Frisk is skeptical and scared at first, but they notice it’s not quite the anxiety that was ingrained into them over the past few weeks. They can hear Sans moving around but he doesn’t try to interact with them again, except to slide some nuts onto the plate for dinner. It’s only by the next day afternoon that Frisk gathers the courage to face Sans again.

Sans, in turn, is very careful around Frisk, staying low and close to their eye level and talking in a soft voice. He explains that Frisk isn’t just a form of entertainment to him anymore, that he didn’t mean to scare them that badly. He ate them so he could heal them more easily, taking away the trauma connections their brain made. That way they can make a clear decision with the memories of everything that happened between them, but they wouldn’t have any trigger reactions that could suddenly pop up anymore. He promises he will take them home, but he asks for a second chance, since he grew really fond of the child.

It does take a while and a lot of tenderness on Sans’ part, but they do end up properly becoming friends.

Sans starts to open up a little more to Frisk, telling that long ago he and the others were seen as protectors of the villages they roamed near. But one day a group of people started traveling around and killing them for payment, claiming to the villagers that they were evil and the villages were trapped under their tyranny. And after hearing it enough times, people started to believe it. They paid to have him slain as well, but no one had counted on Sans’ unusual strength. With the lies and fears having taken roots now though, many more came up the mountain to try and kill him. So Sans had decided never to trust humans or tolerate them so close to his home again.

In turn, Frisk also opens up about their worries about their and Chara’s prophesy. Sans wonders if that didn’t happen already though. After all Frisk took a blade (a small ax) when Chara wanted to take it (to gather wood) and Frisk had entered his maw as well, two times even.

Eventually, Sans takes Frisk back down the mountain to from where they can find their way back home. They are ready to let the kid go forever, only for Frisk to turn around and tell him they’ll see him again sometimes. Once they return they make up a story, and Frisk quickly becomes the child that got lost in the mountains and won an epic battle of words against the King.

In the meantime, Frisk juggles spending time with both Chara and Toriel, but also visits Sans regularly. The two grow even closer to the point where Sans doesn’t know what to do anymore without Frisk’s company, and Frisk starts to feel safe in Sans’ maw.

One day however raiders start to plunder the village and the sound of panic quickly causes Sans to rush over to make sure Frisk is safe. He scared most of the raiding troops away by showing his face and flings away any he can find in the village. He realizes the prophecies might not have been fulfilled yet when he finds Frisk freshly run through with a blade, the one responsible drawing back and ready for another stab. Sans get’s a hold of him though, but he decides it is a little more important to take care of Frisk than to exact some thorough revenge on the guy. So he gives him the deadliest stare he can muster before flinging the human as far away as he can.

Sans starts to panic at Frisk’s condition, but remembering their prophesy he gently slides them into his mouth and swallows. He hears a tiny whimper as he does so. He crouches down to look for the sound and gently questions if they are Chara. He manages to pry the crying child out from hiding under an unhinged door and quickly reassures them that everything will be okay, and Frisk will be fine too.

Many people, especially the village leaders, start to wonder what Sans is doing there, but he refuses to speak. At least until Toriel literally flings her cane into his face and demands to know where here children are. In the end Sans can sooth many people’s nerves when he finally regurgitates an unharmed and healed Frisk.

After that I don’t really know what I want to happen, but the villagers start to see Sans as more of a protector again, Toriel is allowed to take care of Frisk and Chara (as long as Sans provides for the family), and Sans slowly but surely turns into a jungle gym for the children of the village.

 

 

**Notes for the Chapter:**

> Once there was a legend, a king as mountains great
> 
> But for the people at it’s feet, felt little less but hate
> 
> So he ruled the icy mountain peaks, within the thickened mist
> 
> But as he roamed the low one day, then our story did twist
> 
>  
> 
> Then the king came down the mountain and found a child
> 
> Then the king came down the mountain and found a child
> 
>  
> 
> The king he took the child, to keep the joker’s art
> 
> But as the two grew closer a warmth grew in his heart
> 
> One day he let them go, his being filled with sorrow
> 
> But then the child they turned and cried: ´We’ll meet again tomorrow!’
> 
>  
> 
> So the king came down the mountain to meet that child
> 
> So the king came down the mountain to meet that child
> 
>  
> 
> But one day the raiders came, blood and gold in mind
> 
> And in the fight a sharpened blade found the child so kind
> 
> The people felt fear and despair, these men would surely kill
> 
> But as screams rang into the sky the king rushed down the hill
> 
>  
> 
> And the king came down the mountain to save his child
> 
> And the king came down the mountain to save his child
> 
>  
> 
> A blade for the loving heart, a maw to change it’s fate
> 
> For love is so much stronger than old and fading hate
> 
> So if the world turns darker, be brave and stand your ground
> 
> ‘Cause in the kind and lonely souls a family could be found
> 
>  
> 
> Now see that mighty mountain king who loves his human child
> 
> Now see that mighty mountain king who loves his human child


	3. Villages of the Valley

**Summary for the Chapter:**

> Well, it was originally kind of a mix between my Feraltale (mostly in Sans’ appearance and behavior, though it actually is Feraltale’s predecessor) and ‘Mountain King’ AUs. I started fantasizing about it in response to salivaanon’s ‘A little lost soul’ and a not-quit-nightmare I had. And with shamedump’s story, it just popped back to the front of my mind.

**Notes for the Chapter:**

> Some links!:
> 
> 'A little lost soul' by Salivaanon
> 
> 'Protectors of Happy Valley' by Shamedump

A long time ago Sans was an enormous, powerful monster that the Villages of the Valley both liked and hated to see come. On one hand, he would help people in need and save villages from disaster, but once a month he would hunt to devour a child. Many were of the opinion that Sans’ good deeds ware just him taking care of his livestock.

One day, however, a dozen or so years ago, merchants started going around telling that if a child let themself be eaten willingly they would survive the ordeal without any harm, and people also start to notice children stopped disappearing. After that, people quickly start to treat Sans as some kind of deity, organizing banquets after either getting his help or as a diplomatic occasion.

Frisk is a homeless orphan living in one of the villages that is more fearful of Sans. Children of the poorer families usually get picked at random and presented to him kicking and screaming, but they still get spat out alive and unharmed, so that tradition continues. There is also an order of ‘priests’ who are the only ones who can speak ‘hands’, the only language in which Sans can communicate with humans. One day Frisk gets snatched up from the streets and put in front of Sans to be devoured.

Sans, used to seeing trembling and crying children put in front of him, doesn’t think too much of this and eats them. During the rest of the banquet he sits there searching around the room for the child’s anxious parents, but he can’t find them. He reluctantly turns to his ‘priests’ and asks where they are. They answer by telling him no-one will be missing the child, and thus he can experience the pleasure of killing a live meal once more. (Frisk hears this and panics even more.)

Sans is infuriated by this though and roars at the guy before leaving, forgetting Frisk is still tucked away in his belly. Back home in the mountains he spits them back out and tries to calm them down. Needless to say, neither of them get any sleep that night.

The next day Sans manages to catch Frisk again and takes them to his favorite village. At this point, Frisk starts to see some huge differences with their own home. People greet and smile at Sans, children are running around outside without a care even after they see him, and no one is bowing down or hurrying to get out of his way.

They eventually arrive at a slightly larger house where an older lady with soft white hair opening the door. After exchanging a few signs with her, the lady, Toriel, quickly ushers Frisk inside. She washes, clothes and feeds Frisk, before asking them if they would like to come with her to run some errands. Frisk is a little scared and uncertain at first, but decide to go with her since they think they owe her that at least.

They figure out pretty quickly that Toriel is planning to throw a small banquet that wouldn’t be too much trouble for all the villagers.

While going around with Toriel, Frisk get’s to see another side of Sans too. They catch a few glimpses of him listening in with the villagers, dodging playing children and for a few seconds, they can see three men carrying a tree trunk while Sans hollows behind with one more on his own shoulder.

While they are on the way to the baker they even pass him as he just lies there in the middle of the road with a bunch of children around. There are a boy and his little sister bouncing on his belly, a boy walking around with way too large pink slippers making explosion noises with each step and 6 more children waiting their turn, two girls tying ribbons to his horns while a boy tries to put all kinds of different tiny braids in the fur of his coat, and last but not least a girl with his claw in her lap, contently murmuring to herself as she pretends to be doing the monster’s nails with a piece of cloth and some sandpaper.

Sans seems to be fast asleep, but manages to open an eye and grin as Toriel jokingly compliments his claws and to catch the little girl anytime she threatens to fall off his belly.

Frisk stays outside while Toriel talks some things over to keep watching Sans and the kids until a tall guy in his twenties walks over and starts yelling at Sans that he’s a lazybones and shouldn’t just walk away after he offered to help like that. Sans just keeps grinning as the guy keeps getting more worked up until he eventually gives in, shooing the kids off of him and following the young man.

After getting back to Toriel’s house Frisk expresses their confusion over the image of Sans that they grew up with, and what she saw today. So Toriel tells Frisk a bit about Sans’ past, when she was much younger and the village barely known.

(Now, Sans’ backstory is actually based on a ‘ _not sure if it really was a nightmare_ ’.)

Back when Sans still killed people he caught a few children of that village who were playing in the woods nearby. A small boy immediately threw himself in front of the others and said that if Sans was gonna eat anyone it should be him. He had lost his father in a work accident so no one would be crying over losing him. Sans always hated that he had to kill such intelligent creatures as humans to survive, and since that solution would cause a little less grief he agrees and eats the boy.

To Sans’ surprise, the boy actually starts to show sympathy towards him. “It must be so sad to have to hurt people to survive. But you just want to live right, just like everyone else? How is that any different from our beloved cats catching cute little mice?” After a while, Sans can feel himself starting to break. He has learned to block out screams and fighting as they slowly die down, but hearing someone showing understanding for his situation really makes him feel like shit. And the little boy just keeps on consoling him.

Unknown to them the mutual understanding and care opens up both their SOULS to each other and to a constant and non-fatal flow of energy. After a few hours Sans is really surprised that his energy is replenishing (though much slower than usual) but the child in his belly isn’t slowly dying. When he feels his reserves are full enough to survive for a while longer he quickly spits the child back out; a little groggy, but very much alive. They stare at each other in confusion for a while, before Sans flees deeper into the forest.

When the boy get’s back to the village people are astonished to see him alive and hail him as a hero. A week later the kids are playing outside again (since Sans never steals a child from the same village in succession) only to practically bump into him when they stumble into his hiding place from where he had been watching them. While all of the children are frozen in shock Sans turns to the boy from last time and starts fidgeting.

The boy turns to his friends and tells them to go back home, he’ll catch up in a few hours. After they quickly run off to their parents, the boy turns to Sans and asks if he is hungry again. Sans whines and tries to hide his face in the fuzz around his head. To this, the boy says he doesn’t mind that much. If he isn’t gonna harm him like last time and if it keeps everyone from dying (from either hunger or being eaten) he’ll sit through the slime and stickiness.

So Sans gently eats him again, and once he is snuggled up inside the monster’s stomach the young boy introduces himself as Papyrus.

Toriel chuckles and goes on to tell that it was quite a scare when, after she heard Papyrus was eaten by the monster again, she answered a knock on her door and found both of them there. Sans nervously trying to move away, as Papyrus dug his heels into the ground and tried to pull him back by his paw, eagerly chatting away as he tried to introduce her to him.

Once the village accepted that Sans wasn’t randomly going to kill anyone, he became close friends with the boy. Papyrus even asked Sans to be his big brother after a few weeks. And though at first it was mostly Sans humoring him, they have been basically family ever since. It was even him and Toriel that thought the monster sign language.

At one point one of the other children wondered if they could get eaten without getting killed too, and Sans had agreed to do it. And that’s how they found out that Sans can safely feed from a human’s SOUL if there is any trust or sympathy between him and said human. People who get too scared don’t open their SOUL, and thus Sans doesn’t feed on them because in that case, it would kill them.

Sans has been a part of the village ever since, and being eaten by him became a sort of right of passage for the children there. They would choose to be eaten out of their free will, either to be let out immediately if they got too scared or to be eaten again at another time if they liked it, giving Sans a steady and comfortable supply of food.

Some of the villages nearby adopted this same ritual, but there are also some that use it as a way to control their people with fear. Sans had given up to convince them he didn’t mean harm after a while and just went through the ordeal to keep the peace (especially since some people got killed or imprisoned if he refused to eat them). And thus every time after he went to one of those places, he returned here to get the smell of fear out of his nose, the guilty off his shoulders, some actual food in his belly, and to feel warm and welcome with people that actually care about him.

When Toriel leaves to join the festivities, Frisk declines the offer to come with her at first and insist she goes. But as they spend more time thinking, the fact that Sans is a genuinely loved individual here slowly starts to make them wonder. They eventually decide to go and see for themself if there really is that much of a difference even during a meal.

As soon as they enter town hall they instantly notice the contrast in atmosphere. Since they were a poor orphan they couldn’t attend one of the formal banquets, but from the time they had been chosen to be eaten, they can still remember the regal and somber atmosphere, the silence with barely any interaction and some quiet music in the background.

In here, there is color and warmth, both the people and the music lively, with a simple but nice looking buffet. And instead of long tables with gilded chairs and the proper silverware, everyone is sitting on cushions circling around a large firepit with plates in hands and bowls with trash scattered around the room. They eventually find Toriel who is sitting next to Sans with Papyrus on his other side, and after greeting her they go to sit so she is between them and the monster.

After Sans notices them though he suddenly becomes very subdued and even a bit shy. Frisk ties to ignore it at first, but as it starts to make them feel a bit unsettled they ask Toriel why he’s acting like that all of a sudden. To their fear and embarrassment, she actually turns towards him and straight up asks him. Sans turns blue in the face, avoiding to look at both of them as he signs back to her. Toriel lets out a small laugh as she turns back to Frisk, explaining that there is a child in his belly right now and translating he said he didn’t want to scare Frisk more.

Frisk is at first unsettled by this, but they force themself to stay and see what happens next. And Papyrus who leans over and happily chats away about how there is nothing to fear about his brother helps. After about half an hour or so, Sans let’s out a chirp and a couple with a young boy walks over. Frisk recognizes the boy who had been bouncing on Sans belly that afternoon, and the little girl Sans spits out as his little sister. At first, the child looks a little dazed and even disturbed at the liquid on her body as she is placed in her mother’s arms, but she quickly cheers up as she boops’ Sans face with both her slimy hands and giggles at his startled face. He quickly retaliates by playfully licking her face and gently ruffling her hair though.

Again a stark contrast to Frisk’s old home, where they had sometimes seen small families exiting the banquet hall with a shaking and crying child clutched close to their chest.

After this Sans get’s in a considerably more outgoing mood and Frisk finds themself relaxing and enjoying the cheerful atmosphere. At one point Papyrus even drags Sans to the center stage and tells about the jobs they did today as if they are epic battle stories, with the monster just compliantly rolling with it.

When Toriel has to leave to solve a little dispute Frisk even forces themself to go sit right next to Sans. He never actually hurt them after all, and if the people here can consider him a friend the little child would much rather not continue to live in fear of him. When Toriel eventually returns, Frisk is actually inspecting the bones of Sans’ paw, which is placed in their lap, as they listen to Papyrus happily chatting away and telling stories about him and Sans when he was younger.

The next morning Frisk is a little startled to wake up sleeping on top of Sans, with Papyrus propped up against his side, a few more late partiers snoring around them, and Toriel along with a few other people cleaning up and handing out hangover remedies.

Frisk stays in the village with Toriel for a few months after that, learning sign language and not to freak out when Sans pops in up to 4 times in a week. After a while, Frisk does join in with the other children to play with Sans, much to the monster’s joy. They slowly start to get along better and sometimes Sans joins in on sign language classes. At first, Frisk is a little nervous that Sans seems to focus so much on them and their emotions and needs. But as Sans stays kind and genuinely invested with Frisk’s life they slowly start to see him as a close friend (and maybe even the beginnings of the father they never had).

After a few months Frisk volunteers to be eaten for the first time. They are however too scared to move or even look around and as their mind slowly starts to drift closer to irrational panic, Sans spits them out and comforts them before they can lose themself to it.

After that Frisk decides that it might be better to mentally prepare for a while since apparently that fear from the very first time in Sans’ belly isn’t really gone yet. So they spend a lot of time just thinking about the experience, and what their real reason to be so scared was. In the end, the answer was that they let others scare them. Sans himself was never hostile towards them or did anything intentionally scary. If anything he got furious when someone else suggested harming the child, and he barely even knew them back then.

Then they spend a little more time getting to know Sans. They might have gotten to know Sans as a person, but not as the monster he is. Even though they like Sans, they realize the more inhuman parts of him are still a little alien/scary to them. So for a while, they just watch, feel and listen. They listen to the hums and rumbles under his sternum and the deep purrs when they scratch that sweet spot behind his jaw. They knead and rub at the smooth, magic jelly on the outside of his belly (which get’s Sans to purr rather loudly as well). After a while they even get the courage to pry Sans’ maw open, brushing fingers along his sharp fangs and poking his slimy tongue.

Sans finds it a little weird at first, but he can understand that the kid is trying to figure out some stuff. And he’s really surprised when the kid actually asks him directly if they can try getting eaten again. So, that evening, he takes some extra time reassuring them before sending them down his throat.

Frisk forces themself to interact with their surroundings this time and explore his belly. And as they do they realize how soft and warm his magic is, and how soothing those deep purrs around them are. And as Sans too relaxes at their comfort, both their SOULS open up to each other, introducing both of them to another surprise.

Frisk can feel just how much Sans loves and cares about them, no sign language needed at that moment to understand his intent. And Sans finds that Frisk’s determined SOUL has far more energy to offer than any other he has ever encountered before. Even with this safe, peaceful alternative, it suddenly replenishes his magic and energy to its full capacity again, like eating a full meal after undereating for years. It worries him at first, but as Frisk snuggles closer without any sign of alarm or ill effects he decides to relax and keep an eye out, just in case.

After that, Frisk decides to go and stay with Sans. Toriel is a little disappointed to see the child go, but she knows Sans adores them and will take good care of them (or else).

After that, Frisk goes everywhere with Sans, sometimes in his belly if said situation is a dangerous job that needs fixing (safely tucked away and doubling as a little human battery if he needs more magic). The people in the villages get to know them too and the more fearful ones start treating them as his ‘highest priest’. They don’t mind, Frisk is happy that people will believe them over all others when they say he isn’t going to hurt anyone even if they don’t bow low enough, and Sans enjoys watching those magistrates squirm as they can’t do anything against the child translating his honest words.

Not everyone can quit entirely shake the image that had been molded around Sans throughout history, but the Villages of the Valleys start becoming and feeling like a much safer place.


	4. Warfell

**Summary for the Chapter:**

> Holy gosh! How did I never tell you guys about the very first Undertale AU I ever made. Oh, I can remember it like it was yesterday. I was a little bit late to the Undertale party and I just found out about Underfell…

**Notes for the Chapter:**

> It’s basically a version of Underfell but with an ‘what it?’ element.

The history is almost entirely the same, but right before Ariel died Asgore was able to retrieve Chara’s soul. Blaming humans for the death of his child, Asgore declared that he’d take the souls, become a god, and destroy all of humanity for their crimes. And after many years of training his subjects to be ruthless and collecting the souls of the humans that fell down, he now has seven and breaks the barrier.

To his shock though, the little souls are completely spent and disappear. So the monsters stay underground for 15 more years, while scouts go out to spy on humans and secretly collect more souls for the officers that will lead the war.

I imagined this AU with the meeker versions of Fell Sans. He mostly tries to avoid the village and instead spends a lot of time in the woods, talking to Toriel at her door, telling jokes, finding comfort, reporting her the news. When he tells her that the seventh soul has been taken she busts out in tears and asks Sans to make her a promise.

“There will be many in this war that never asked for this. That never wanted for this to happen, or even have locked us up in the first place. Please, my friend, take care of the innocents. Give them hope for a peaceful future.”

When Sans agrees, Toriel thanks him, there is a moment of silence, and then some dust starts to drift from underneath the Ruins’ door.

Those 15 years that are spent preparing Sans moves into Toriel’s house to be away from the violence. There he makes his own preparations and befriends a little golden Flower with whom he can grief the lady’s death together.

5 years after the war started an 8-year-old Frisk is trying desperately to survive. They had been locked up in the basement as punishment when their town was attacked, and they stayed there for a week as the monsters moved on. Now they roam the broken streets, looking for food, water, and shelter.

While doing so though they see a monster through the dust and rubble and flee. They try to desperately escape, but the monster always seems to pop us in the places they try to run to. Eventually, they become so erratic that they run straight into a broken traffic sign and knock themself out.

To their surprise they wake up….period, that’s a big surprise on its own, they’re alive! But they’re also in a large room, which is surprisingly cozy despite being entirely concrete. But there are a bunch of bunk beds with colorful blankets and posters all over the place, and there are some toys and even electronics that haven’t been put away properly.

They go exploring, finding also a bathroom, a large room full of couches, chairs, and beanbags, and eventually a room with a large stove and rows of tables. And in each of the rooms, there are at least a few children hanging around or playing.

They are eventually approached by a girl called June who sits them down and tells them that they are safe here. Frisk is worried about the monsters outside, but June explains that there is a barrier around their bonker. One that is similar to but weaker than the one that kept monsters trapped underground. A monster can only come in if it is let in. She explains that all of them came from attacked towns and cities and were brought here to recover, be kept safe, and eventually returned to the humans. She isn’t able to get far in her explanation though before Frisk hears there is a knock at the door at the other side of the room. A little girl with a periwinkle headband and a wooden sword runs over and asks who’s there.

 

“who.”

 

“Who who?”

 

“owls? i thought i was hearing children before!”

 

The little girl giggles at the answer and reaches for the doorknob. Frisk jumps to their feet, fearing that the little girl will accidentally let in a monster. And they think their fear became reality when through the gap of the door they can see a blood-red eye, a sharp-fanged grin, a bloodied skeletal hand and an ax gleaming in the light.

Frisk instantly shoots back towards the room with all the bunk beds at the back, yelling at everyone that can hear that a monster got in. Behind them, they can hear a scream, right as they dive into the space between the closet and the wall. There they stay, shivering in fear with their hands over their ears.

It stays still for a long time though, or at least there isn’t a sound that gets past the hands blocking their ears. So they open their eyes and are startled to see several of the other children peeking into their hiding place with the skeletal monster standing right behind them. As soon as they see Frisk watching them, multiple of the children start talking to comfort them, but they can’t understand a word of what is being said. So the monster gently shoos the kids away and sits down in front of Frisk.

He introduces himself as Sans, caretaker of the lost children. He treasures Frisk that everything is okay and everyone is safe. He spends a little while explaining everything to Frisk, with a little talking flower that is growing out of the dirt he has in his pocket to back him up. Once Frisk isn't as frightened anymore he calls for a few of the children to help them feel at ease and come out of hiding.

When they eventually get back to the dining room, Frisk finds out that the scream was one of the kids, Kevin, who got excited that Sans brought back some rabbits he caught for the boy to cook. And the blood on Sans’ hands was from said rabbits.

Frisk stays with the group for a little over a month, in which time they get used to Sans and learn that even though he is a bit impatient and tells jokes that make the older children cover the younger one’s ears, he is a very affectionate and dedicated caretaker.

One day though, Sans rounds up all the kids and they go outside. Sans leads them towards an underground network where a few human soldiers stand there waiting for them. They quickly usher most of the kids into the tunnels and hand over a few crates to Sans. Apparently Sans had been able to strike up a deal with the humans: He helps children escape and delivers them back to the humans, and the humans provide him with the medications and other harder-to-obtain tools so he can care properly for more children. And mustard, there are bottles of mustard there as well.

Six of the children stay by Sans’ side though, even when the soldiers ask if they still insist on staying with Sans.

Frisk is too intimidated by the military men’s yelling and decides to stay with Sans too.

Together that help each other and any new kids Sans brings back, and they try to survive in this war-filled world in the hopes that one day there will be peace.

 

* * *

 

 

Now, background information!

 

The six other kids staying with Sans are:

 

June, 17 years, straw hat and a hunting rifle, justice soul

 

Kevin, 14 years, waiters apron and a spade, kindness soul

 

Percy, 10 years, colorblind glasses and a touchpad, perseverance soul

 

Indy and Brenda, twins, 9 years, loose pants/sneakers and sweatband/brass knuckles, integrity and brave souls

 

Patricia (Patty), 5 years, blue headband and wooden sword, patience soul

 

And yes, all of them (including Frisk) are the reincarnations of the 7 souls.

 

\---------------------

 

Patty has been with Sans the longest, since she was a little baby. Sans found her and her dying mother under the rubble and after a lot of tears he promised her he would do his best to take care of her daughter.

 

\---------------------

 

Sans has 3 human souls of his own, each of them given to him willingly so he could protect the children. One of them is Patty’s mom.

 

\---------------------

 

Yes, there are collars. Sans has one for each of the children. The first time they went out just to play Frisk was disgusted by this, throws their own away, and tries to run off. They can’t get far though before they get caught by Papyrus, who has leadership over one of the villages nearby. Before he can kill Frisk though, Brenda who had been following Frisk intervenes and tells him that they are ‘one of Sans’ mongrels’. Papyrus is skeptical, but when they go to confront Sans about it he confirms it as well.

The monsters that had been closest and friends to Sans in the underground have a deal with him. Any humans that wear a collar, marked as his, are to be left alone. They won’t save the kid if they are caught by another monster, but they won’t hurt them.


End file.
